The present invention relates to an apparatus configured to recover carbon dioxide (CO2) and a method for recovering CO2.
The greenhouse effect due to CO2 has been regarded as one of the causes of global warming. In order to suppress this phenomenon, much research and development to prevent or suppress the release of CO2 into the atmosphere have been carried out. Because CO2 is generated mainly by the combustion of fossil fuels, it is desired that exhaust gas generated by the combustion of fossil fuels be emitted to the atmosphere after CO2 contained in the gas is appropriately reduced or removed therefrom.
Japanese Patent Application Publication No. 2008-62165 discloses an apparatus, which is installed in power generation facilities of a thermal power plant, which uses a large amount of fossil fuel, and which is configured to remove and recover CO2 contained in exhaust gas by bringing exhaust gas from a boiler into contact with a CO2 absorbent, and which is configured to store the recovered CO2 without discharging the same into the atmosphere. Japanese Patent Application Publication No. 2008-62165 discloses a regeneration tower configured to separate and remove CO2 gas by applying heat to an absorbent that has absorbed CO2 and is configured to regenerate the absorbent. In addition, Japanese Patent Application Laid-Open No. 2008-62165 discusses a method for compressing the CO2 removed in the regeneration tower by using a plurality of compressors to a state in which the compressed CO2 can be injected into the ground or into an oilfield to be stored therein. Furthermore, Japanese Patent Application Publication No. 2008-62165 discloses a method for improving the energy efficiency of the entire CO2 recovery apparatus by exchanging heat between a part of the absorbent regenerated by the regeneration tower and compression heat generated by a plurality of compressors, by supplying the absorbent heated as described above to a tower bottom portion of the regeneration tower, and by using the heated absorbent supplied to the regeneration tower as a heat source for heating the absorbent.